The L-arginine-nitric oxide pathway

Human breath analysis; Clinical application and measurement: An overview

Human breath has been recognized as a complex yet predictive mixture of volatile organic compounds (VOCs) and inorganic gas species that can be utilized to non-invasively diagnose common diseases. Current laboratory techniques such as gas chromatography/mass spectrometry (GC/MS) and high-performance liquid chromatography (HPLC), are capable of VOC detection down to ppm concentrations. However, these methods are expensive, non-portable, require pre-processing of the exhaled VOCs, and expert operators, making them unsuitable for wide-spread use. Portable gas sensors have various advantages over other methods used in gas analysis, including ease of transportation, reduced treatment costs, fast results, and improved patient experience. Recent advancements in gas sensing technologies have enabled such devices to be used to diagnose, predict, and monitor a wide range of diseases and conditions, however, many challenges need still need to be addressed (i.e., sensitivity and selectivity) before they can be employed for such applications. Although nanotechnology has greatly improved the performance of gas sensor materials and their capacity to detect VOCs in human breath, issues around repeatability and accuracy remain, as well as adequateness due to the close proximity of the human body and the sensor device. This review focuses on how recent advancements in nanotechnology and solid-state materials have enabled VOC gas sensors to evolve into miniaturized, sensitive and selective devices for monitoring human breath in clinical applications. An introduction to the key aspects of breath analysis, including sources of VOCs in human breath and their role in disease diagnosis, is discussed. Furthermore, the current limitations and future prospects of such gas sensors for breath monitoring applications are also discussed in detail.

Accelerating inflammatory resolution in humans to improve endothelial function and vascular health: Targeting the non-canonical pathway for NO

BACKGROUND

Chronic cardiovascular diseases (CVD) are characterised by low-grade systemic inflammation in part due to reduced nitric oxide (NO) bioavailability associated with endothelial dysfunction. Bioavailability of NO can be enhanced by activation of the non-canonical pathway, through increased dietary inorganic nitrate consumption with the potential to attenuate inflammation.

METHODS

We sought to determine whether dietary inorganic nitrate influences the inflammatory response in models of localised (cantharidin-induced blisters) and systemic inflammation (typhoid vaccine), in healthy male volunteers and conducted two clinical trials; Blister-NITRATE and Typhoid-NITRATE respectively.

RESULTS

We show that dietary nitrate attenuates endothelial dysfunction following typhoid vaccine administration and accelerates resolution of cantharidin-induced blisters. Both phenomena were associated with an increased level of pro-resolving mediators consequent to a reduction in the expression and activity of pro-inflammatory monocytes. Moreover, we show that leukocytes of the monocyte lineage express the nitrite reductase XOR, that may drive localised nitrite reduction to elevate NO (and cGMP) to drive the protective phenotype.

CONCLUSIONS

Inorganic nitrate improves endothelial function in the setting of systemic inflammation. Whilst the immediate inflammatory response appeared unaffected by inorganic nitrate treatment, during the resolution phase of the acute inflammatory response lower levels of pro-inflammatory classical inflammatory and intermediate monocytes and attenuated levels of inflammatory cytokines and chemokines were evident. We propose that this reflects a pro-resolution phenotype that may be of potential therapeutic benefit in patients with established CVD.

CLINICAL TRIAL REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; unique identifiers NCT02715635, NCT03183830.

Arginine Therapy for Pain in Sickle Cell Disease: A Phase-2 Randomized, Placebo-Controlled Trial

We present a prospective randomized, placebo-controlled trial of intravenous arginine in patients 3-21 years hospitalized with sickle cell disease vaso-occlusive pain episodes (SCD-VOE) at two tertiary-care children's hospitals. Participants were randomized into 1 of 3 arms: Standard-dose (SD; 100 mg/kg/dose) every 8 h, Loading-dose (200 mg/kg followed by SD), or Placebo. The primary outcome was total parenteral opioid use (TPO). Secondary outcomes included time-to-crisis-resolution, pain scores, patient-reported outcomes (PROs), arginine bioavailability, and biomarkers of oxidative stress/mitochondrial function. Of 1548 patients screened, 108 were randomized (36 per study-arm; mean 12.6 ± 3.8 years, 52% female, and 65% hemoglobin-SS). This study did not meet its primary endpoint. TPO, time-to-crisis-resolution, pain scores, and PROs at discharge were similar across arms. Post hoc sensitivity analyses of children 5-16 years old demonstrated nearly double TPO utilization in those receiving placebo versus arginine (n = 87, p = 0.056), achieving significance in patients with plasma arginine < 60 μM. Arginine was low at presentation in 79% of patients (mean 50 ± 28 μM), and increased with arginine therapy (p < 0.001). Arginine bioavailability at VOE presentation inversely correlated with time-to-crisis-resolution (r = -0.39, p = 0.01) after placebo, an association eliminated by arginine supplementation (r = -0.04, p = 0.70). A dose-dependent increase in platelet-mitochondrial activity occurred after arginine versus no change after placebo (p < 0.001); plasma protein-carbonyl levels, a measure of oxidative stress, decreased after arginine therapy (p < 0.001) but increased in the placebo group (p = 0.02). SCD-VOE is associated with an acquired arginine deficiency that correlates with worse clinical outcomes. Arginine improved mitochondrial function and decreased oxidative stress compared to placebo, with clinically relevant opioid-sparing becoming significant in children with the lowest arginine concentration. TRIAL REGISTRATION: Registered with ClinicalTrials.gov (NCT02536170) in August 2015.

Impact of Acute Antioxidant and Tetrahydrobiopterin (BH4) Administration on Locomotor Muscle Microvascular Function in Patients With Heart Failure

BACKGROUND

Peripheral microvascular dysfunction is a hallmark feature of both heart failure with reduced ejection fraction (HFrEF) and preserved ejection fraction (HFpEF) pathophysiology, due partly to impairments in nitric oxide signaling secondary to tetrahydrobiopterin (BH4) deficiency and oxidative stress.

METHODS

Using a randomized, double-blind, placebo-controlled crossover design, this study examined the impact of enteral BH4 (10 mg/kg), an antioxidant cocktail (AOx), and coadministration of these 2 agents (BH4+AOx) on microvascular function in patients with HFrEF (n=14, 64±10 years) and HFpEF (n=19, 74±9 years). Passive limb movement was utilized to assess locomotor muscle microvascular function, and biomarkers of inflammation and oxidative damage were measured.

RESULTS

Compared with placebo, the peak change in leg blood flow was not statistically different after AOx administration (HFrEF, P=0.60; HFpEF, P=0.61), but improved following BH4 (P=0.033) and BH4+AOx (P=0.019) in both HFrEF (placebo: 234±31; BH4: 357±45; BH4+AOx: 355±49 mL/min) and HFpEF (placebo: 269±33; BH4: 367±47; BH4+AOx: 394±65 mL/min). The total hyperemic response to passive limb movement (leg blood flow area under the curve) was not statistically different across treatments in patients with HFrEF (P=0.29), but increased following BH4 (P=0.016) and BH4+AOx (P=0.040) in the HFpEF group. CRP (C-reactive protein) was lower following BH4 (P=0.007) and BH4+AOx (P=0.007) in HFpEF (placebo: 4268±547; BH4: 2721±391; BH4+AOx: 2779±376 ng/mL), but was not statistically different in HFrEF (P=0.39).

CONCLUSIONS

Together, these results provide new evidence for the efficacy of acute BH4 administration to improve some aspects of locomotor muscle microvascular function in patients with HFrEF and HFpEF, with no apparent benefit of AOx administration, alone or in combination with BH4, in either group. These findings lend further conceptual support for the nitric oxide pathway as a modifiable target in the treatment of heart failure.

A novel TGR5 agonist Sauchinone ameliorates IMQ induced murine psoriasis by regulating macrophage polarization

INTRODUCTION

G-protein-coupled bile acid receptor (TGR5) is a member of G-protein-coupled receptor (GPCR) superfamily that participates in regulating macrophage polarization and resolving inflammatory diseases. Sauchinone is Saururus chinensis derived natural product with anti-inflammatory activity. Still, whether Sauchinone could regulate macrophage polarization and its direct target remain to be explored.

OBJECTIVES

This study aims to demonstrate the direct target of Sauchinone, its influences on macrophage polarization and its pharmacological actions on imiquimod (IMQ) induced mouse psoriasis model.

METHODS

We detected the TGR5 agonistic activity of Sauchinone in mouse/human TGR5/ cAMP response elements (CRE)/HEK293 stable cell lines and verified its direct effect on mouse/human macrophages by Cellular thermal shift assay (CETSA) and by examining downstream CREB phosphorylation. Afterwards, we discovered the activity of Sauchinone on regulating macrophage M1/M2 polarization in Bone marrow-derived macrophages (BMDM) by detecting M1/M2 markers through Enzyme-linked immunosorbent assay (ELISA), Real-time polymerase chain reaction (RT-qPCR), Western blot and Fluorescence-activated cell sorting (FACS). We further utilized macrophages derived from Tgr5-/- mice or introduced TGR5 specific inhibitor, TGR5 si-RNA and PKA inhibitor to determine whether Sauchinone regulated macrophage polarization through TGR5. We then prepared Sauchinone cream formulation to disclose its pharmacological action in IMQ induced mouse psoriasis model and used FACS and immunofluorescence to verify its action on macrophage polarization in psoriatic skin. Moreover, we tested the protective actions of Sauchinone cream in IMQ treated Tgr5-/- mice to verify that Sauchinone alleviated psoriasis in TGR5 dependent manner.

RESULTS

Sauchinone is a novel TGR5 agonist without human/mouse species selectivity. Sauchinone rectified macrophage M1 polarization through activating TGR5. Topical use of Sauchinone cream ameliorated IMQ induced psoriasis and regulated macrophage polarization in psoriatic skins. Sauchinone cream alleviated psoriasis in TGR5 dependent manner.

CONCLUSION

Our work identified Sauchinone as a novel TGR5 agonist that could ameliorate IMQ induced murine psoriasis by regulating macrophage polarization.

Vasoplegia in Heart, Lung, or Liver Transplantation: A Narrative Review

Vasoplegia is a pathophysiologic state of hypotension in the setting of normal or high cardiac output and low systemic vascular resistance despite euvolemia and high-dose vasoconstrictors. Vasoplegia in heart, lung, or liver transplantation is of particular interest because it is common (approximately 29%, 28%, and 11%, respectively), is associated with adverse outcomes, and because the agents used to treat vasoplegia can affect immunosuppressive and other drug metabolism. This narrative review discusses the pathophysiology, risk factors, and treatment of vasoplegia in patients undergoing heart, lung, and liver transplantation. Vasoplegia in this patient population is associated with acute kidney injury, hospital length of stay, and even survival. The mechanisms of vasoplegia in this patient population likely involve multiple pathways, including nitric oxide synthase, cyclic guanylate cyclase, cytokine release, hydrogen sulfide, adrenal axis abnormalities, and vasopressin deficiency. Contributors to vasoplegia in this population include mechanical circulatory support such as extracorporeal membrane oxygenation and cardiopulmonary bypass, organ ischemia time, preexisting infection, and medications such as angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and excessive sedation. Treatment of vasoplegia in this population begins with conventional catecholamines and vasopressin analogs. Occasionally, agents, including methylene blue, hydroxocobalamin, and angiotensin II, are administered. Though retrospective literature suggests a hemodynamic response to these agents in the transplant population, minimal evidence is available to guide management. In what follows, we discuss the treatment of vasoplegia in the heart, lung, and liver transplant populations based on patient characteristics and potential risk factors associated with non-catecholamine agents.

Intravenous peptides and amino acids for erectile dysfunction: a narrative review of current applications and future directions

INTRODUCTION

Erectile dysfunction (ED) pathophysiology involves complex interactions between vasculogenic, hormonal, and neurological mechanisms, with endothelial dysfunction and oxidative stress playing crucial roles. There is growing interest in intravenous (IV) peptides and amino acids as potential therapeutic options for ED treatment.

AREAS COVERED

This narrative review examines recent developments in peptide and amino acid therapies for ED, focusing on PT-141, PnPP-19, L-arginine, and L-citrulline. The literature search utilized PubMed to identify relevant English-language publications up to October 2024, emphasizing studies from the past decade.

EXPERT OPINION

IV peptides and amino acids offer promising therapeutic options for ED through mechanisms of action distinct from PED5 inhibitors. PT-141 and PnPP-19 show efficacy through central nervous system activation and nitric oxide regulation, while L-arginine and L-citrulline enhance endothelial function. Although evidence suggests potential benefits, large-scale clinical trials are needed to establish safety profiles, optimal dosing regimens, and possible synergistic effects with existing ED treatments.

Immunomodulatory Effects of L-Arginine-Modified Silkworm Pupae Protein Enteral Nutrition on Murine Intestinal Morphology and Immunity

L-arginine, a semi-essential amino acid, is well-documented for its role in nitric oxide (NO) synthesis, its anti-inflammatory properties, and its modulation of immune responses. Studies suggest it may improve gut barrier function and reduce inflammation in conditions such as colitis or sepsis. However, its specific efficacy in diabetic enteropathy (a complication of diabetes involving intestinal dysfunction, inflammation, and neuropathy) is less studied. To verify whether L-arginine and silkworm pupae components have a role in the treatment of diabetic enteropathy via the regulation of other cytokines and suppression of CD4+ T lymphocyte proliferation, a special medical-purpose formula containing both of these components was tested. For the first time, we have integrated L-arginine and silkworm pupae protein into enteral nutrition formulations for testing its anti-inflammatory potential. We have found that these formulations can improve the characteristics of diabetic intestinal inflammation through nutrient-modulating effects and nutritional efficacy. In addition, L-arginine (L-arginine, L-arg) enhances the immunomodulatory effects of special medical purpose formulas for diabetes mellitus. We utilized an oxidative stress model of small intestinal epithelial cells induced by high glucose and an inflammation model of the small intestine triggered by lipopolysaccharide in mice. The aim was to further investigate the protective effects of L-arginine and enteral nutritional preparations derived from silkworm pupae protein components on the intestinal tract. This research seeks to establish a theoretical foundation for understanding how L-arginine and these nutritional preparations regulate intestinal inflammation in vivo.

Estradiol levels are differentially associated with pulse wave velocity in trauma-exposed premenopausal women with and without PTSD

Arterial stiffness is a well-known risk factor for cardiovascular disease. Although estradiol (E2) is known to be cardioprotective, the available data point to a growing cardiovascular disease risk in women before menopause due to posttraumatic stress disorder (PTSD). The present study aimed to investigate the effects of E2 on arterial compliance in trauma-exposed premenopausal women, with and without a clinical diagnosis of PTSD. We hypothesized that E2 will be differentially associated with pulse wave velocity (PWV) in women with PTSD (PTSD+, n = 45) and without PTSD (PTSD-, n = 47). Estradiol and PWV were measured during two separate study visits. Serum E2 levels were measured via the quantitative sandwich enzyme-linked immunoassay technique (ELISA) and log-transformed due to non-normal distribution. Carotid to femoral applanation tonometry was used to measure PWV. Our analyses revealed an overall weak and nonsignificant correlation between E2 and PWV (r = -0.119, P = 0.350). However, when examining each group, we found a negative association between E2 and PWV in PTSD- (r = -0.466, P = 0.004). In contrast, we found an unexpected positive association between E2 levels and PWV in PTSD+ (r = 0.360, P = 0.037). Furthermore, a multiple linear regression revealed that E2 was predictive of PWV in PTSD- only, even after accounting for the phase of the menstrual cycle, age, body mass index, diastolic blood pressure, and PTSD symptom severity (R2 = 0.670, P = 0.005). Interestingly, we also found lower levels of E2 in PTSD+ than PTSD- (1.4 ± 0.4 vs. 1.6 ± 0.4 pg/mL, P = 0.022). These findings suggest that PTSD may inhibit the protective effects of E2 on arterial compliance in women before menopause.NEW & NOTEWORTHY In trauma-exposed premenopausal women, we found that serum estradiol (E2) was a predictor of pulse wave velocity (PWV) only in the absence of a posttraumatic stress disorder (PTSD) diagnosis, even after accounting for the phase of the menstrual cycle, age, body mass index, diastolic blood pressure, and PTSD symptom severity. Moreover, E2 levels were lower in women with PTSD than in those without PTSD. We collected E2 and PWV during two separate visits and controlled for the menstrual cycle phase in our analyses.

Recent advances in protein and amino acid nutritional dynamics in relation to performance, health, welfare, and cost of production

Amino acids are the foundation of numerous metabolic and physiological pathways for skeletal muscle accretion, internal organ development, skeletal development, and immune function. One widely studied subject in monogastric nutrition is dietary crude protein. However, birds do not have a crude protein requirement but have a clear requirement for essential amino acids. As individual amino acid requirements of swine and poultry are investigated and modern feed formulation tools and feed-grade amino acids are available cost-effectively, the dynamics of how we look at crude protein in the feed have evolved. With the modern tools available, nutritionists are able to formulate the feed to meet the amino acids required for optimal performance of animals. This approach reduces the excess nitrogen in the feed, making the diets friendlier for the gut, reducing substrates for harmful proliferating bacteria, reducing nitrogen excretion in manure, and improving the ecology and sustainability. Apart from growth, amino acids have a functional role in the metabolic and physiological pathways. Amino acids like threonine and arginine have additional functional roles in intestinal turnover, immune function, wound healing, vasodilation and oxidative, and heat stress alleviation. Such specific amino acids can be increased in the diet to support the physiological needs during the growth of animals without increasing the unwanted dietary nitrogen content. As the industry moves toward reducing crude protein while meeting the essential amino acid needs, more research is needed to understand the requirement of specific lower limiting and non-limiting amino acids as well as the dynamics of those amino acids in health, welfare, cost of production and ecological impact in poultry and swine production.

Unveiling the Role of Fractionated Graphene Oxide in Nitric Oxide Scavenging

The feasibility of saturating aqueous anoxic solutions with in situ-generated high-purity nitric oxide (NO) is shown herein. A methemoglobin assay estimated the average nitric oxide concentration to be ca. 20 ± 3 µM. Graphene oxide aqueous dispersions were prepared by ultrasound-assisted extra exfoliation. These dispersions, including unpurified (pristine) samples and samples purified from transition metal impurities (bulk) fractions (bulkGO) and (nano) separated fractions (nanoGO) in a range of 0.5 to 14 kDa were prepared with ppm level concentrations. A robust and reproducible chemiluminescence (CL) assay validated the interaction between graphene oxide and NO in a luminol-based system. The results showed a significant increase in NO scavenging activity within the bulkGO fractions to nanofractions ranging from 14 to 3.5 kDa. The different reaction pathways underlying the transformation of nitric oxide are being evaluated, focusing on understanding how its presence or absence affects these processes. Our kinetic model suggests a significant difference in nitric oxide regulation; nanoGO demonstrates an interception rate seventy-times higher than that achieved through CL quenching.

A Narrative Review of the Expression and Role of Nitric Oxide in Endometriosis

Nitric oxide (NO) is a key signaling molecule involved in cellular communication and plays a critical role in various biological processes. Given its dual role in the pathogenesis of endometriosis, we conducted a systematic literature review to explore its mechanisms further. Numerous studies have investigated the expression and role of NO in various diseases, including those in the field of gynecology. However, the expression and role of NO in endometriosis remain a topic of ongoing debate. Therefore, we conducted a comprehensive literature review using the Cochrane Library, EMBASE, Google Scholar, PubMed, and SCOPUS databases to evaluate the induction and role of NO in the pathogenesis of endometriosis. Of the 27 papers ultimately reviewed, 22 (81.4%) reported that NO contributes to the pathogenesis of endometriosis, 3 (11.1%) suggested that NO acts as a protective mechanism against endometriosis, and 2 studies (7.4%) found no association between NO and the pathogenesis of endometriosis. The expression and levels of NO in endometriosis were associated with pregnancy, infertility, menstruation, and pelvic pain. Research conducted on rats and mice demonstrated that NO, nNOS, eNOS, and iNOS play significant roles in the development of endometriosis. Most studies suggested that increased NO levels are associated with the pathogenesis of endometriosis.

Getting to the Heart of the Matter: Exploring the Intersection of Cardiovascular Disease, Sex and Race and How Exercise, and Gut Microbiota Influence these Relationships

Cardiovascular disease (CVD) is the leading cause of death worldwide, with physical inactivity being a known contributor to the global rates of CVD incidence. CVD incidence, however, is not uniform with recognized sex differences as well and racial and ethnic differences. Furthermore, gut microbiota have been associated with CVD, sex, and race/ethnicity. Researchers have begun to examine the interplay of these complicated yet interrelated topics. This review will present evidence that CVD (risk and development), and gut microbiota are distinct between the sexes and racial/ethnic groups, which appear to be influenced by acculturation, discrimination, stress, and lifestyle factors like exercise. Furthermore, this review will address the beneficial impacts of exercise on the cardiovascular system and will provide recommendations for future research in the field.

Physiological Mechanisms Driving Microcirculatory Enhancement: the Impact of Physical Activity

Background

Physical activity induces many beneficial adaptive changes to blood vessel microcirculation, ultimately improving both health and exercise performance. This positions it an effective non-pharmacological therapeutic approach for the rehabilitation of patients with various chronic diseases. Understanding the impact of different types of physical activities on microcirculation and elucidating their physiological mechanisms is crucial for optimizing clinical practice.

Methods

A comprehensive literature search was performed across multiple databases including PubMed, EBSCO, ProQuest, and Web of Science. Following a rigorous screening process, 48 studies were selected for inclusion into the study.

Results

Existing studies demonstrate that various forms of physical activity facilitate multiple positive adaptive changes at the microcirculation level. These include enhanced microvascular dilation-driven by endothelial cell factors and mechanical stress on blood vessels-as well as increased capillary density. The physiological mechanisms behind these improvements involve the neurohumoral regulation of endothelial cell factors and hormones, which are crucial for these positive effects. Physical activity also ameliorates inflammation markers and oxidative stress levels, upregulates the expression of silent information regulator 2 homolog 3, genes for hypoxia-inducible factors under hypoxic conditions, and induces favorable changes in multiple hemodynamic and hemorheological parameters. These structural and functional adaptations optimize myocardial blood flow regulation during exercise and improve both oxygen transport and utilization capacity, which are beneficial for the rehabilitation of chronic disease patients.

Conclusions

Our provides a reference for using physical activity as a non-pharmacological intervention for patients with chronic conditions. This framework includes recommendations on exercise types, intensity, frequency, and duration. Additionally, we summarize the physiological mechanisms through which physical activity improves microcirculation, which can inform clinical decision-making.

Effect of Nuts on Anthropometric and Glycemic Indexes and Blood Pressure in Secondary Cardiovascular Prevention: A Systematic Review and Meta-analysis of Randomized Controlled Trials

CONTEXT

Nut-enriched diets have a positive impact on cardiovascular risk factors, such as body mass, blood pressure, and fasting blood glucose. However, studies in individuals undergoing secondary cardiovascular prevention show controversial results.

OBJECTIVE

This systematic review with meta-analysis assessed the effect of nut supplementation on anthropometric, glycemic, and blood pressure indices in patients with atherosclerotic cardiovascular disease, as well as the frequency of adverse events.

DATA SOURCES

Six databases were used for the search-PubMed, Cochrane Library, EMBASE, BVS (Biblioteca Virtual da Saude), Web of Science, and ClinicalTrials.gov-until February 2023, with no language restrictions.

DATA EXTRACTION

The Cochrane Handbook for Systematic Reviews of Interventions methodology and the PICOS (Population, Intervention, Comparison, Outcome, Setting/design) strategy were used. Seven independent reviewers were involved in data extraction and resolution of disagreements. Certainty of the evidence was evaluated using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) system.

DATA ANALYSIS

From 5187 records identified, 6 publications containing data referring to 5 randomized clinical trials (n = 436) were included in the final analyses. The nuts evaluated were almonds, pecans, Brazil nuts, and mixed nuts, with portions that varied between 5 g and 85 g (median: 30 g/day). The intervention period varied between 6 and 12 weeks. The nuts had no effect on fasting glucose and anthropometric indices, although the certainty of the evidence for most of these outcomes was low or very low. They also had no effect on systolic (mean difference [MD]: -1.16 mmHg [95% CI, -5.68 to 3.35], I2 = 0%-moderate certainty of evidence) or diastolic (MD: 0.10 mmHg [95% CI, -2.30 to 2.51], I2 = 0%-high certainty of evidence) blood pressure. It was not possible to aggregate data on adverse events.

CONCLUSION

Nut supplementation had no effect on blood pressure, fasting glucose, or anthropometric profile in the context of atherosclerotic cardiovascular disease.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42020163456.

Advances in moyamoya disease: pathogenesis, diagnosis, and therapeutic interventions

Moyamoya disease (MMD) is a type of cerebrovascular disease characterized by occlusion of the distal end of the internal carotid artery and the formation of collateral blood vessels. Over the past 20 years, the landscape of research on MMD has significantly transformed. In this review, we provide insights into the pathogenesis, diagnosis, and therapeutic interventions in MMD. The development of high-throughput sequencing technology has expanded our understanding of genetic susceptibility, identifying MMD-related genes beyond RNF213, such as ACTA2, DIAPH1, HLA, and others. The genetic susceptibility of MMD to its pathological mechanism was summarized and discussed. Based on the second-hit theory, the influences of inflammation, immunity, and environmental factors on MMD were also appropriately summarized. Despite these advancements, revascularization surgery remains the primary treatment for MMD largely because of the lack of effective in vivo and in vitro models. In this study, 16 imaging diagnostic methods for MMD were summarized. Regarding therapeutic intervention, the influences of drugs, endovascular procedures, and revascularization surgeries on patients with MMD were discussed. Future research on the central MMD vascular abnormalities and peripheral circulating factors will provide a more comprehensive understanding of the pathogenic mechanisms of MMD.

Impact of tadalafil on cardiovascular and organ dysfunction induced by experimental sepsis

BACKGROUND

Sepsis is a life-threatening condition that affects the cardiovascular and renal systems. Severe hypotension during sepsis compromises tissue perfusion, which can lead to multiple organ dysfunction and death. Phosphodiesterase 5 (PDE5) degrades intracellular cyclic guanosine monophosphate (cGMP) levels which promotes vasodilatation in specific sites. Our previous studies show that inhibiting cGMP production in early sepsis increases mortality, implying a protective role for cGMP production. Then, we hypothesized that cGMP increased by tadalafil (PDE5 inhibitor) could improve microcirculation and prevent sepsis-induced organ dysfunction.

METHODS

Rats were submitted to cecal ligation and puncture (CLP) sepsis model and treated with tadalafil (2 mg/kg, s.c.) 8 hours after the procedure. Hemodynamic, inflammatory and biochemical assessments were performed 24 hours after sepsis induction. Moreover, the effect of tadalafil on the survival of septic rats was evaluated for 5 days.

RESULTS

Tadalafil treatment improves basal renal blood flow during sepsis and preserves it during noradrenaline infusion. Sepsis induces hypotension, impaired response to noradrenaline, and increased cardiac and renal neutrophil infiltration, in addition to increased levels of plasma nitric oxide and lactate. None of these dysfunctions were changed by tadalafil. Additionally, tadalafil treatment did not increase the survival rate of septic rats.

CONCLUSIONS

Tadalafil improved microcirculation of septic animals; however, no beneficial effects were observed on macrocirculation and inflammation parameters. Then, the potential benefit of tadalafil in the prognosis of sepsis should be evaluated within a therapeutic strategy covering all sepsis injury mechanisms.

PFKFB3 Connects Glycolytic Metabolism with Endothelial Dysfunction in Human and Rodent Obesity

Obesity and type 2 diabetes (T2D) increase cardiovascular risk, largely due to altered metabolic state. An early consequence of T2D/obesity is the loss of endothelial function and impaired nitric oxide (NO) signaling. In blood vessels, endothelial nitric oxide synthase (eNOS) synthesizes NO to maintain vessel homeostasis. The biological actions of NO are compromised by superoxide that is generated by NADPH oxidases (NOXs). Herein we investigated how altered metabolism affects superoxide/NO balance in obesity. We found that eNOS expression and NO bioavailability are significantly decreased in endothelial cells (ECs) from T2D patients and animal models of obesity. In parallel, PFKFB3, a key glycolytic regulatory enzyme, is significantly increased in ECs of obese animals. EC overexpression of wild-type and a cytosol-restricted mutant PFKFB3 decreased NO production due to increased eNOS-T495 phosphorylation. PFKFB3 also blunted Akt-S473 phosphorylation, reducing stimulus-dependent phosphorylation of S1177 and the activation of eNOS. Furthermore, PFKFB3 enhanced the activities of NOX1 and NOX5, which are major contributors to endothelial dysfunction. Prolonged exposure of ECs to high glucose or TNFα, which are hallmarks of T2D, leads to increased PFKFB3 expression. These results demonstrate a novel functional relationship between endothelial metabolism, ROS, and NO balance that may contribute to endothelial dysfunction in obesity.

Nitric oxide in exercise physiology: past and present perspectives

Nitric oxide (NO) is a ubiquitous signaling molecule known to modulate various physiological processes, with specific implications in skeletal muscle and broader applications in exercise performance. This review focuses on the modulation of skeletal muscle function, mitochondrial adaptation and function, redox state by NO, and the effect of nitrate supplementation on exercise performance. In skeletal muscle function, NO is believed to increase the maximal shortening velocity and peak power output of muscle fibers. However, its effect on submaximal contraction is still undetermined. In mitochondria, NO may stimulate biogenesis and affect respiratory efficiency. NO also plays a role in the redox state within the skeletal muscle, partially through its interaction with respiratory chain enzymes and transcriptional regulators of antioxidant production. Nitrate supplementation leads to an increased bioavailability of NO in skeletal muscle. Thus, nitrate supplementation has been investigated for its ability to impact performance outcomes in endurance and resistance exercise. The effect of nitrate supplementation on endurance exercise is currently indecisive, although evidence indicates that it may extend the time to exhaustion in endurance exercise. Alternatively, the effect of nitrate supplementation on resistance exercise performance has been less studied. Limited research indicates that nitrate supplementation may improve repetitions to failure. Further research is needed to investigate the influence of training status, age, sex, and duration of supplementation to further elucidate the impact of nitrate supplementation on exercise performance.

Oral microbiome and nitric oxide biomarkers in older people with mild cognitive impairment and APOE4 genotype

Apolipoprotein E4 (APOE4) genotype and nitric oxide (NO) deficiency are risk factors for age-associated cognitive decline. The oral microbiome plays a critical role in maintaining NO bioavailability during aging. The aim of this study was to assess interactions between the oral microbiome, NO biomarkers, and cognitive function in 60 participants with mild cognitive impairment (MCI) and 60 healthy controls using weighted gene co-occurrence network analysis and to compare the oral microbiomes between APOE4 carriers and noncarriers in a subgroup of 35 MCI participants. Within the MCI group, a high relative abundance of Neisseria was associated with better indices of cognition relating to executive function (Switching Stroop, rs = 0.33, P = 0.03) and visual attention (Trail Making, rs = -0.30, P = 0.05), and in the healthy group, Neisseria correlated with working memory (Digit Span, rs = 0.26, P = 0.04). High abundances of Haemophilus (rs = 0.38, P = 0.01) and Haemophilus parainfluenzae (rs = 0.32, P = 0.03), that co-occurred with Neisseria correlated with better scores on executive function (Switching Stroop) in the MCI group. There were no differences in oral nitrate (P = 0.48) or nitrite concentrations (P = 0.84) between the MCI and healthy groups. Linear discriminant analysis Effect Size identified Porphyromonas as a predictor for MCI and Prevotella intermedia as a predictor of APOE4-carrier status. The principal findings of this study were that a greater prevalence of oral P. intermedia is linked to elevated genetic risk for dementia (APOE4 genotype) in individuals with MCI prior to dementia diagnosis and that interventions that promote the oral Neisseria-Haemophilus and suppress Prevotella-dominated modules have potential for delaying cognitive decline.

Chronic inorganic nitrate supplementation does not improve metabolic health and worsens disease progression in mice with diet-induced obesity

Inorganic nitrate (NO3-) has been proposed to be of therapeutic use as a dietary supplement in obesity and related conditions including the metabolic syndrome (MetS), type II diabetes, and metabolic dysfunction-associated steatotic liver disease (MASLD). Administration of NO3- to endothelial nitric oxide synthase-deficient mice reversed aspects of MetS; however, the impact of NO3- supplementation in diet-induced obesity is not well understood. Here we investigated the whole body metabolic phenotype and cardiac and hepatic metabolism in mice fed a high-fat, high-sucrose (HFHS) diet for up to 12 mo of age, supplemented with 1 mM NaNO3 (or NaCl) in their drinking water. HFHS feeding was associated with a progressive obesogenic and diabetogenic phenotype, which was not ameliorated by NO3-. Furthermore, HFHS-fed mice supplemented with NO3- showed elevated levels of cardiac fibrosis and accelerated progression of MASLD including development of hepatocellular carcinoma in comparison with NaCl-supplemented mice. NO3- did not enhance mitochondrial β-oxidation capacity in any tissue assayed and did not suppress hepatic lipid accumulation, suggesting it does not prevent lipotoxicity. We conclude that NO3- is ineffective in preventing the metabolic consequences of an obesogenic diet and may instead be detrimental to metabolic health against the background of HFHS feeding. This is the first report of an unfavorable effect of long-term nitrate supplementation in the context of the metabolic challenges of overfeeding, warranting urgent further investigation into the mechanism of this interaction.NEW & NOTEWORTHY Inorganic nitrate has been suggested to be of therapeutic benefit in obesity-related conditions, as it increases nitric oxide bioavailability, enhances mitochondrial β-oxidation, and reverses metabolic syndrome in eNOS-/- mice. However, we here show that over 12 months nitrate was ineffective in preventing metabolic consequences in high fat, high sucrose-fed mice and worsened aspects of metabolic health, impairing cholesterol handling, increasing cardiac fibrosis, and exacerbating steatotic liver disease progression, with acceleration to hepatocellular carcinoma.

Bariatric surgery blunts nitrate-mediated improvements in cardiovascular function of overweight women by interfering with gastric S-nitrosothiol formation

Inorganic nitrate (NO3-) and nitrate-rich foods have been shown to exert antioxidative effects and lower blood pressure in experimental animal models and human clinical studies. The specific handling of nitrate, including its enterosalivary recirculation, secretion into saliva, oral microbial reduction to nitrite (NO2-), and the pH-dependent nitrosative capacity in the stomach have all been recognized as being important for nitrate's beneficial effects. Obesity is of major health concern worldwide and associated with increased cardiovascular risk; whether nitrate lowers blood pressure and improves endothelial function in this setting has not been investigated. We here tested the hypotheses that i) nitrate elicits cardiovascular benefits in overweight women; and ii) these beneficial effects would be diminished in women who underwent bariatric Roux-en-Y gastric bypass (RYGB) surgery. Our controlled clinical trial included 15 women with prior RYGB surgery and 15 overweight female controls. All participants received a single dose of 0.1 mmol/kg/day nitrate in the form of a beetroot extract for 14 days. Blood collection, 24-h ambulatory blood pressure measurements and endothelial function tests were performed before and after nitrate treatment. Plasma nitrite, nitrate, and S-nitrosothiol (RSNO) concentrations were determined by ozone-based reductive chemiluminescence while thiobarbituric acid reactive substances (TBARS) and total antioxidant capacity (TAC) were measured using plate-reader based assays. Nitrate reduced blood pressure and improved endothelial function in controls, but not in women with prior bariatric surgery. Nitrate also increased circulating nitrate/nitrite and RSNO levels in controls, but the latter was blunted following RYGB surgery despite even larger increases in nitrite concentrations. Similarly, nitrate increased antioxidant responses in controls but not in women with prior bariatric surgery. This is the first study to show that nitrate exerts beneficial cardiovascular effects in obesity and that the morphological/functional modifications elicited by RYGB surgery abrogates nitrate's effectiveness by preventing gastric RSNO formation.

Concurrent consumption of cocoa flavanols and caffeine does not acutely modulate working memory and attention

PURPOSE

Consumption of cocoa flavanols and caffeine might acutely enhance cognition, particularly in synergy. Due to the use of multifaceted tasks in prior research, it is unclear precisely which cognitive functions are implicated. Here we aimed to assess the acute effects of the (joint) ingestion of cocoa flavanols and caffeine on temporal attention, spatial attention, and working memory.

METHODS

In four separate sessions of a randomized, double-blind, placebo-controlled, crossover trial, 48 young adult participants consumed a placebo drink, a cocoa flavanols (415 mg) drink, a caffeine (215 mg) drink, and a drink containing both concurrently. In each session, after ingestion, we tested performance in three cognitive tasks. We tested temporal attention in a dual-target rapid serial visual presentation paradigm, known to elicit the attentional blink, in which the time between the targets was manipulated. We measured spatial attention in a visual search task, where we varied the number of distractors that appeared simultaneously with the target. We tested working memory in a delayed recall task, in which the number of stimuli to be remembered was manipulated.

RESULTS

We obtained the expected performance pattern in each task, but found no evidence for modulation of response accuracy or reaction times by the ingestion of either substance, nor of their combined ingestion, even in the most challenging task conditions.

CONCLUSIONS

We conclude that, even when jointly ingested, neither the tested amount of cocoa flavanols nor caffeine have acute effects that are robustly measurable on cognitive tasks that target attention and working memory specifically.

G protein-coupled estrogen receptor activation attenuates cisplatin-induced CKD in C57BL/6 mice: An insight into sex-related differences

Gender contributes to differences in incidence and progression of chronic kidney disease (CKD) post-cisplatin therapy. This study aims at investigating the potential effect of G1 compound, a GPER agonist, on attenuating cisplatin-induced CKD. To induce CKD in male, intact female, and ovariectomized (OVX) mice, CKD was induced by injecting two cycles of 2.5 mg/kg cisplatin with a 16-day recovery period between cycles). G1 (50 or 100 μg/kg was administered daily for 6 weeks. Severity of renal damage was more pronounced in males than females. Interestingly, OVX resulted in renal damage that is non-significant compared to males and significantly higher than females. G1 improved renal function and blood flow as evidenced by reduction of serum creatinine and elevation of creatinine clearance, NO production, and reduction of ET1. This renoprotective effect could be attributed to its immunomodulatory effect regulated by TGF-β that shifted the balance to favor anti-inflammatory cytokine production (increased IL-10) rather than pro-inflammatory cytokines (decreased Th17 expression). Reduction of TGF-β activation also inhibited epithelial-to-mesenchymal transition that eventually ameliorated CKD development. Antioxidant potential of G1 has been demonstrated by upregulation of Nrf2 and subsequent antioxidant enzymes. These data suggest that G1 could be a promising therapeutic tool to attenuate CP-induced CKD.

Evidence-based sports supplements: A redox analysis

Despite the overwhelming number of sports supplements on the market, only seven are currently recognized as effective. Biological functions are largely regulated through redox reactions, yet no comprehensive analysis of the redox properties of these supplements has been compiled. Here, we analyze the redox characteristics of these seven supplements: bicarbonates, beta-alanine, caffeine, creatine, nitrates, carbohydrates, and proteins. Our findings suggest that all sports supplements exhibit some degree of redox activity. However, the precise physiological implications of these redox properties remain unclear. Future research, employing unconventional perspectives and methodologies, will reveal new redox pixels of the exercise physiology and sports nutrition picture.

Targeting endothelial KCa channels in vivo restores arterial and endothelial function in type 2 diabetic rats

OBJECTIVE

This study tested the hypothesis that administration of the KCa channel activator SKA-31 restores endothelium-dependent vasodilation in vivo in Type 2 Diabetic (T2D) rats.

BACKGROUND

Acute treatment of isolated resistance arteries from T2D rats and humans with SKA-31 significantly improved endothelium-dependent vasodilation. However, it is unknown whether these in situ actions translate to intact vascular beds in vivo.

METHODS

Male Sprague Dawley (SD) and T2D Goto-Kakizaki (GK) rats (26-32 weeks of age) were injected intraperitoneally with either drug vehicle or 10 mg/kg SKA-31. Doppler ultrasound imaging was used to record reactive hyperemia/flow-mediated dilation (FMD) in the femoral artery following release of an occlusion cuff on the distal hind limb, along with diameter changes in the left main coronary artery in response to inhaled isoflurane (2 % → 5 %).

RESULTS

Vehicle treated SD rats exhibited a robust and reversible FMD response, the magnitude and time course of which did not differ in SD rats treated with SKA-31. In contrast, only a weak FMD response was observed in vehicle-treated T2D GK rats, whereas prior SKA-31 administration restored FMD to the level observed in control SD rats. Exposure of SD rats to 5 % isoflurane caused robust coronary artery dilation, which was not altered by prior treatment with SKA-31. In T2D GK rats, 5 % isoflurane inhalation alone did not increase coronary artery diameter, however, a strong vasodilatory response was observed following SKA-31 treatment. SKA-31 administration did not modify intrinsic heart rate responses in either protocol.

CONCLUSIONS

Enhancement of KCa channel activity in vivo restores endothelium-dependent vasodilation in T2D rats that exhibit peripheral endothelial dysfunction.

The NITRATE-OCT study-inorganic nitrate reduces in-stent restenosis in patients with stable coronary artery disease: a double-blind, randomised controlled trial

Background

Coronary angioplasty and stent insertion is a first line treatment for patients with coronary artery disease, however it is complicated in the long-term by in-stent restenosis (ISR) in a proportion of patients with an associated morbidity. Despite this, currently there are no effective treatments available for the prevention of ISR. Repeat percutaneous revascularisation carries increased risks of major adverse cardiovascular events and a higher incidence of stent failure. In this study we report the efficacy of dietary inorganic nitrate in the prevention of ISR in a prospective, double-blind, randomised controlled trial.

Methods

NITRATE-OCT is a double-blind, randomised, single-centre, placebo-controlled phase II trial. 300 patients who were planned to undergo percutaneous coronary intervention (PCI) and drug eluting stent (DES) implantation for stable angina were randomised on a 1:1 basis to receive a daily dose of either dietary inorganic nitrate or placebo for 6 months. Block randomisation was used and patients stratified according to diabetes status. The patients then underwent quantitative coronary angiography (QCA) at baseline and at 6 months and optical coherence tomography at 6 months to quantify ISR. The primary endpoint was the QCA quantified decrease of in-stent/in-segment diameter from the baseline measure at 6 months i.e., in-stent and in-segment late-lumen loss (LLL). The study is registered with ClinicalTrials.gov, number NCT02529189.

Findings

From November 1st 2015 and March 31st 2020, NITRATE-OCT enrolled 300 patients with angina, with 150 each randomised to receive 70 mL of nitrate-containing beetroot juice or placebo (nitrate-deplete) juice for 6 months. Procedural characteristics were similar between the groups. The primary endpoint was available in 208 patients: 107 and 101 in the nitrate and placebo groups, respectively. There was a statistically significant effect of inorganic nitrate on both primary endpoints: in-stent LLL decreased by 0.16 mm (95% CI:0.06-0.25; P = 0.001) with mean = 0.09 ± 0.38 mm in the inorganic nitrate group versus 0.24 ± 0.33 mm in the placebo group; (P = 0.0052); and in-segment LLL decreased by 0.24 mm (95% CI:0.12-0.36; P < 0.001) with mean = 0.02 ± 0.52 mm in the inorganic nitrate group and 0.26 ± 0.37 mm in the placebo group (P = 0.0002). Inorganic nitrate treatment was associated with a rise in the plasma nitrate concentration of ∼6.1-fold and plasma nitrite (NO2 -) of ∼2.0-fold at 6 months. These rises were associated with sustained decreases in systolic blood pressure (SBP) at 6 months compared to baseline with a change SBP of -12.06 ± 15.88 mmHg compared to the placebo group of 2.52 ± 14.60 mmHg (P < 0.0001).

Interpretation

In patients who underwent PCI for stable coronary artery disease, a once-a-day oral inorganic nitrate treatment was associated with a significant decrease in both in-stent and in-segment LLL.

Funding

This trial and KSR was funded by the National Institute for Health and Care Research (NIHR) (DRF-2014-07-008) and NIHR ACL, HW and this study were supported by The NIHR Barts Biomedical Research Centre, IC was funded by The North and East London Clinical Research Network, CL, GM were funded by The Barts Charity Cardiovascular Programme MRG00913 and MO was funded by The British Heart Foundation Project Grant PG/19/4/33995.

Understanding Endothelial Dysfunction and Its Role in Ischemic Stroke After the Outbreak of Recanalization Therapies

Despite recent advances in treatment options, stroke remains a highly prevalent and devastating condition with significant socioeconomic impact. Recanalization therapies, including intravenous thrombolysis and endovascular treatments, have revolutionized stroke management and prognosis, providing a promising framework for exploring new therapeutic strategies. Endothelial dysfunction plays a critical role in the pathophysiology, progression, and prognosis of stroke. This review aims to synthesize the current evidence regarding the involvement of the nitric oxide (NO)/endothelium pathway in ischemic stroke, with a particular focus on aging, response to recanalization therapies, and therapeutic approaches. While significant progress has been made in recent years in understanding the relationship between endothelial dysfunction and stroke, many uncertainties persist, and although treatments targeting this pathway are promising, they have yet to demonstrate clear clinical benefits.

Serum Malondialdehyde-Modified Low-Density Lipoprotein Level May Be a Biomarker Associated with Aortic Stiffness Among Patients Undergoing Peritoneal Dialysis

BACKGROUND

Serum malondialdehyde-oxidized low-density lipoprotein (MDA-oxLDL) is associated with atherosclerosis and increased risk of cardiovascular disease (CVD). Vascular calcification frequently occurs with arterial stiffness in patients on peritoneal dialysis (PD). This cross-sectional study aimed to elucidate the correlation between aortic stiffness and MDA-oxLDL levels in patients on PD.

METHODS

Overall, 92 patients on PD were included. The carotid-femoral pulse wave velocity (cfPWV) was evaluated using cuff-based volumetric displacement, and blood samples were obtained from all patients. Aortic stiffness was classified based on cfPWV values (>10 m/s indicating aortic stiffness). Serum MDA-ox-LDL levels were quantified using commercial enzyme-linked immunosorbent assay kits.

RESULTS

In total, 33 (35.9%) patients were classified into the aortic stiffness group. Factors, including systolic blood pressure (SBP), serum triglyceride levels, C-reactive protein levels, age, weight, body mass index (BMI), waist circumference, MDA-oxLDL levels, and diabetes mellitus (DM) prevalence, were significantly higher in the aortic stiffness group. Multivariable logistic regression analysis revealed significant associations between aortic stiffness and MDA-oxLDL levels, BMI, and SBP. Furthermore, multivariable forward stepwise linear regression analysis revealed serum MDA-oxLDL levels as a significant independent predictor of cfPWV values.

CONCLUSIONS

Serum MDA-oxLDL levels correlate positively with cfPWV values and may predict aortic stiffness among PD patients, highlighting its potential role in assessing CVD risk in this population.

Decompression Illness After Technical Diving Session in Mediterranean Sea: Oxidative Stress, Inflammation, and HBO Therapy

SCUBA diving poses risks due to pressure changes during descent (compression) and ascent (decompression). Decompression sickness (DCS) occurs due to gas bubble formation as the pressure decreases, causing joint pain, numbness, dizziness, or even paralysis and death. Immediate treatment involves 100% oxygen to help eliminate inert gases and hyperbaric oxygen therapy (HBOT), which is essential to reduce gas emboli formation and inflammation, thus improving symptoms. We evaluated oxy-inflammation biomarkers in the saliva and urine of nine subjects pre- and post-technical dive on the Haven wreck (GE, Italy). A case of DCS occurred during the dive. The injured diver was treated immediately with O2 and transported to the hyperbaric center of "ASST Ospedale Ca Granda" in Milan. He was treated following the U.S. Navy Treatment Table 5 at 2.8 ATA and the day after with Table 15 at 2.4 ATA. Venous blood and urine samples were collected before and after each HBO treatment. Our study shows that dive increased oxy-inflammation biomarkers (ROS +126%; lipid peroxidation +23%; interleukins-6 +81%, -1β +19%, and TNFα +84%) and nitric oxide metabolites levels (+36%). HBOT after a DCS episode reduced oxidative stress, lowering the very high marker of lipid peroxidation (8-iso-PGF2α), and inhibited inflammatory interleukins. Overall, HBOT improved physiological responses in the diver affected by DCS.

Comparative Evaluation of the Chemical Components and Anti-Inflammatory Potential of Yellow- and Blue-Flowered Meconopsis Species: M. integrifolia and M. betonicifolia

Background/Objectives:Meconopsis has long been used in traditional Tibetan medicine to treat various inflammatory and pain-related conditions. However, blue-flowered Meconopsis (M. betonicifolia) is becoming increasingly scarce due to overharvesting. As a potential alternative, yellow-flowered Meconopsis (M. integrifolia) shows promise but requires comprehensive characterization. This study aimed to evaluate and compare the anti-inflammatory potential of yellow- and blue-flowered Meconopsis species. Methods: Liquid chromatography-mass spectrometry (LC-MS) techniques were used to analyze the chemical profiles of yellow- and blue-flowered Meconopsis. Putative targets of shared constituents were subjected to GO and disease enrichment analysis. The LPS-induced RAW264.7 macrophage model was employed to assess anti-inflammatory effects. Metabolomics was applied to gain mechanistic insights. Results: LC-MS revealed over 70% chemical similarity between species. Enrichment analysis associated targets with inflammation-related pathways. In macrophage assays, both species demonstrated dose-dependent antioxidative and anti-inflammatory activities, with yellow Meconopsis exhibiting superior efficacy. Metabolomics showed modulation of key inflammatory metabolic pathways. Conclusions: This integrative study validated yellow-flowered Meconopsis as a credible alternative to its blue-flowered counterpart for anti-inflammatory applications. Metabolic profiling provided initial clues regarding their multi-targeted modes of action, highlighting their potential for sustainable utilization and biodiversity conservation.

An enantioselective fluorescent probe for detecting arginine and glutamic acids

Amino acids are important chiral compounds in the human body, and are important basic components that make up the human body and play an important role in the human body. Among them, different enantiomers of an amino acid may have different roles, and different types of amino acids can be interconverted. However, the content of D-amino acids is much lower than that of L-amino acids, which is difficult to be detected. At present, many of the potential roles of D-amino acids, such as the conversion of D-amino acids to each other, have not yet been fully revealed. Hence, we synthesized fluorescent probe (R)-5 by condensation of 1,1'-Bi-2-naphthol (BINOL) and 2-(Aminomethyl)pyridine with Schiff base, which can recognize both D-arginine and D-glutamic acid at low concentrations. Meanwhile, (R)-5 can be applied to paper-based sensors for the detection of arginine and glutamate in living cells and for food amino acid detection.

The place of beta-adrenergic receptor blockers in the treatment of arterial hypertension: From bench-to-bedside

Arterial hypertension is a multifaceted condition influenced by numerous pathophysiological factors. The key contributors to its pathogenesis encompass an unhealthy lifestyle, dysregulation of the sympathetic nervous system, alterations in the activity of adrenergic receptors, disruptions in sodium metabolism, structural and functional abnormalities in the vascular bed, as well as endothelial dysfunction, low-grade inflammation, oxidative stress etc. Despite extensive research into the mechanisms of arterial hypertension development over the centuries, its pathogenesis remains incompletely understood, and the selection of an effective treatment strategy continues to pose a significant challenge. Arterial hypertension is characterized by a diminished sensitivity of the β-adrenergic system, leading to the utilization of β-adrenergic blockers and other antihypertensive drugs in its treatment. This review delves into the mechanisms of action of beta-adrenergic receptor blockers in the treatment of hypertension and their respective effects.

Coadministration of PEGylated apohemoglobin and haptoglobin can limit vascular dysfunction in the microcirculation and prevent acute inflammation

Unfortunately, during pathological conditions resulting in chronic hemolysis cell-free hemoglobin (Hb) is released into the circulation that releases free heme, resulting in several complications. One approach to prevent these toxicities is the administration of supplemental scavenger proteins, haptoglobin (Hp) and hemopexin (Hpx). The goal of this body of work is to objectively measure the levels of vascular reactivity and inflammatory profiles after an infusion of acellular hemoglobin in animals that were given a coadministration of PEGylated human apohemoglobin (PEG-apoHb), a hemopexin (Hpx)-mimetic that can scavenge free heme from hemoglobin, together with human plasma-derived Hp that can scavenge dimerized Hb. Using intravital microscopy, Golden Syrian hamsters instrumented with a dorsal window chamber were used to evaluate the in vivo effects of four experimental groups that were then challenged with a hypovolemic injection (10% of the animal's blood volume) of human Hb (hHb, 5 g/dL). The four experimental groups consisted of: 1) lactated Ringer's solution (control), 2) PEG-apoHb only, 3) Hp only, and 4) PEG-apoHb + Hp. The microvascular hemodynamics (diameter and flow) in arterioles and venules were recorded at baseline, 20 min after treatment, and 20 min after hHb challenge. Systemic parameters (blood pressure and heart rate), blood gases (pH, Pco2, and Po2), blood parameters (Hb concentration and hematocrit), and multiorgan functionality/inflammation were also measured. Our results suggest that coadministration of PEG-apoHb + Hp as a booster before the infusion of acellular hemoglobin significantly prevented vasoconstriction in the microcirculation, significantly increased the number of functional capillaries, and significantly reduced inflammation.NEW & NOTEWORTHY Coadministration of PEGylated human apohemoglobin (PEG-apoHb)-a hemopexin (Hpx) mimetic that can scavenge free heme-and human plasma-derived haptoglobin (Hp) that can scavenge hemoglobin (Hb), reduces microcirculatory dysfunction and cardiac and kidney inflammation in a Hb-challenge model.

Brown garlic: A nutritionally improved garlic with therapeutic value in asthma treatment via modulation of S-nitrosothiols

Nitric Oxide (NO) regulates important physiological functions. Garlic (Allium sativum) is an important food component consumed fresh and processed for thousands of years. It has high L-arginine, which contributes to the NO system in the body. Both garlic and NO impact important physiological processes. Here we produced brown garlic, with significantly higher nutritional and therapeutic value compared to fresh and black garlic. Lower exhaled NO was recorded in asthmatic mice fed with brown garlic but with higher blood SNOs and no change in eNOS and iNOS expression. Lung biopsy showed reduced eosinophil accumulation in asthmatic mice fed with brown garlic. Real-time PCR and Western blot analyses indicated high expression of antioxidant genes but reduced interleukin genes, IL-4, IL-5, IL-6, IL-13, IL1β, and TNF-α brown garlic-fed asthmatic mice as compared to that in fresh and black garlic-fed asthmatic mice. This study provides the first comprehensive and conclusive insight into the nutritional benefits of brown garlic and its therapeutic value for the treatment of asthma in animals.

Causal relationship between C-reactive protein and ischemic stroke caused by atherosclerosis: A Mendelian randomization study

OBJECTIVES

This study investigates the association between C-reactive protein (CRP) and ischemic stroke caused by large artery atherosclerosis (LAA).

METHODS

Five Mendelian Randomization (MR) methodologies were used for two-sample analyses: Inverse Variance Weighting (IVW), MR-Egger regression, Weighted Median (WM), Simple Mode, and Weighted Mode. CRP exposure data were obtained from aggregated summary statistics from a meta-analysis of genome-wide association studies (GWAS) in individuals of European ancestry (n = 343,524; UK Biobank). Stroke data were used as the outcome, with specific dataset details for relevant subtypes (cases = 40,585, controls = 406,111).

RESULTS

In the CRP GWAS dataset, selected single nucleotide polymorphisms (SNPs) as instrumental variables (IVs) showed genome-wide significance and a causal relationship with CRP, particularly in relation to LAA stroke. IVW indicated a robust causal connection between CRP and LAA stroke (Beta = 0.151, SE = 0.055, P = 0.006). The WM approach supported this relationship (Beta = 0.176, SE = 0.082, P = 0.033). However, MR-Egger regression suggested a potential absence of a causal link (Beta = 0.098, SE = 0.077, P = 0.206), with minimal influence from horizontal pleiotropy (Intercept = 0.0029; P = 0.317). The Simple mode found no significant association (Beta = 0.046, SE = 0.217, P = 0.834), while the Weighted mode revealed a significant causal association (Beta = 0.138, SE = 0.059, P = 0.020) between CRP and LAA stroke.

CONCLUSIONS

MR analysis provides evidence for a potential causal relationship between CRP and an increased risk of LAA stroke.

Benefits of dark chocolate intake on retinal vessels functionality: a randomized, blind, crossover clinical trial

There is a lack of knowledge about the effect of flavanols-rich dark chocolate intake on the anatomy and functionality of retinal vessels. The aim of this study prospective, randomized, blind, crossover clinical trial (ClinicalTrials.gov Identifier: NCT05227248, 07/02/2022) was to evaluate the effect of dark-chocolate intake on the functionality and anatomy of the retinal vessels in healthy subjects using dynamic vessel analyzer (DVA) and optical coherence tomography angiography (OCT-A). Twenty eyes of 20 healthy subjects (mean age, 24.4 ± 1.6 years; 12 females) were enrolled. Participants were randomized to consume 20 g of dark chocolate or 7.5 g of milk chocolate. Visual function, DVA and OCT-A parameters were evaluated before chocolate consumption and two hours later. One week later, the same participants were tested before and after consuming the opposite chocolate. Using OCT-A, no differences were disclosed in terms of perfusion density changes after dark-chocolate and milk-chocolate intake analyzing all chorioretinal plexuses (p > 0.09 in all analyses). Using DVA, a significant increase in the arterial dilation percentage after flicker stimulation was disclosed comparing baseline (2.750 ± 2.054%) with values after the dark chocolate intake (4.145 ± 3.055%, p = 0.016). This difference was not disclosed after the milk chocolate intake (p = 0.465). We disclosed that a reasonable amount of flavanols-rich chocolate in healthy subjects has benefic functional short-term effects in retinal vessels measured with DVA. This suggests a potential role of dark chocolate intake on retinal vessels. Further studies with long-term follow-up are warranted to show if the chronic assumption of dark chocolate could play a favorable role in the prevention of retinal diseases.

Levels of Plasma Endothelin-1, Circulating Endothelial Cells, Endothelial Progenitor Cells, and Cytokines after Cardiopulmonary Bypass in Children with Congenital Heart Disease: Role of Endothelin-1 Regulation

Congenital heart disease (CHD) can be complicated by pulmonary arterial hypertension (PAH). Cardiopulmonary bypass (CPB) for corrective surgery may cause endothelial dysfunction, involving endothelin-1 (ET-1), circulating endothelial cells (CECs), and endothelial progenitor cells (EPCs). These markers can gauge disease severity, but their levels in children's peripheral blood still lack consensus for prognostic value. The aim of our study was to investigate changes in ET-1, cytokines, and the absolute numbers (Ɲ) of CECs and EPCs in children 24 h before and 48 h after CPB surgery to identify high-risk patients of complications. A cohort of 56 children was included: 41 cases with CHD-PAH (22 with high pulmonary flow and 19 with low pulmonary flow) and 15 control cases. We observed that Ɲ-CECs increased in both CHD groups and that Ɲ-EPCs decreased in the immediate post-surgical period, and there was a strong negative correlation between ET-1 and CEC before surgery, along with significant changes in ET-1, IL8, IL6, and CEC levels. Our findings support the understanding of endothelial cell precursors' role in endogenous repair and contribute to knowledge about endothelial dysfunction in CHD.

High serum levels of reactive nitrogen species and low total antioxidant capacity in patients with resistant hypertension compared to those in age- gender matched healthy controls, controlled hypertension and follow up with propranolol treatment in the extended APPROPRIATE trial

OBJECTIVES

To perform a comparative analysis of the extended APPROPRIATE trial of measures of reactive nitrogen species and antioxidant capacity in patients having resistant hypertension with controlled hypertension and healthy controls.

RESULTS

Mean serum NO2- and NOx levels were significantly lower and mean AOC was significantly higher in patients with controlled hypertension (n = 38) and healthy controls (n = 38) compared to resistant hypertension (RHTN) patients (n = 40) at the pre-intervention stage (p < 0.001). The serum NO2-, NOx and AOC levels of both controlled hypertension and healthy controls were comparable to those of the RHTN patients following treatment with propranolol (n = 18). Considering all samples (n = 114) we noted that there were significant weak and moderate positive correlations between NO2- levels with systolic blood pressure (SBP) and diastolic blood pressure (DBP) (r = 0.396, p < 0.001 and r = 0.292, p = 0.004) as well as total NOx levels with SBP and DBP (r = 0.636 and r = 0.480 respectively, p < 0.001). Conversely, there was a significant negative correlation between AOC levels with SBP and DBP (r= -0.846 and r = -0.626 respectively, p < 0.001).

Nitric Oxide-Activated Bioorthogonal Codelivery Nanoassembly for In Situ Synthesis of Photothermal Agent for Precise and Safe Anticancer Treatment

The development of bioorthogonal activation in drug release represents a promising avenue for precise and safe anticancer treatment. However, two significant limitations currently hinder their clinical application: i) the necessity for separate administration of the drug precursor and its corresponding activator, leading to poor drug accumulation and potential side effects; ii) the reliance on exogenous metal or organic activators for triggering bioorthogonal activation, which often exhibit low efficiency and systemic toxicity when extending to living animals. To overcome these limitations, a nitric oxide (NO)-mediated bioorthogonal codelivery nanoassembly, termed TTB-NH2@PArg, which comprises a precursor molecular (TTB-NH2) and amphipathic polyarginine (PArg) is developed. In TTB-NH2@PArg, PArg serves as both self-assembled nanocarrier for TTB-NH2 and a NO generator. In tumor microenvironment (TME), the TME-specific generation of NO acts as a gas activator, triggering in situ bioorthogonal bond formation that transforms TTB-NH2 into TTB-AZO. This tumor-specific generation of TTB-AZO not only serves as a potential photothermal agent for effective tumor inhibition but also induces fluorescence change that enables real-time monitoring of bioorthogonal activation. This study presents a drug codelivery approach that enables precise and safe control of bioorthogonal activation for anticancer treatment, improving cancer therapy efficacy while minimizing side effects.

Severe Allergy as a Chronic Inflammatory Condition From a Systems Biology Perspective

Persistent and unresolved inflammation is a common underlying factor observed in several and seemingly unrelated human diseases, including cardiovascular and neurodegenerative diseases. Particularly, in atopic conditions, acute inflammatory responses such as those triggered by insect venom, food or drug allergies possess also a life-threatening potential. However, respiratory allergies predominantly exhibit late immune responses associated with chronic inflammation, that can eventually progress into a severe phenotype displaying similar features as those observed in other chronic inflammatory diseases, as is the case of uncontrolled severe asthma. This review aims to explore the different facets and systems involved in chronic allergic inflammation, including processes such as tissue remodelling and immune cell dysregulation, as well as genetic, metabolic and microbiota alterations, which are common to other inflammatory conditions. Our goal here was to deepen on the understanding of an entangled disease as is chronic allergic inflammation and expose potential avenues for the development of better diagnostic and intervention strategies.

Nitrate and Nitrite Exposure Induces Visual Impairments in Adult Zebrafish

Nitrate and nitrite have emerged as increasingly common environmental pollutants, posing significant risks to various forms of life within ecosystems. To understand their impact on the visual system of zebrafish, adult zebrafish were exposed to environmentally relevant concentrations of nitrate (10 mg/L) and nitrite (1 mg/L) for 7 days. Visual behaviors were examined using optomotor and avoidance response. The eyeballs of the zebrafish were collected for H&E staining, IHC, and qPCR. Exposure decreased visual behavior and the thickness of most retinal layers. Exposure decreased expression of pax6a, pax6b, gpx1a, and bcl2a. Exposure increased expression of esr1, esr1a, esr2b, cyp19a1b, sod1a, nos2a, casps3, and tp53, and increased retinal brain aromatase expression by IHC. Collectively, our findings demonstrate that nitrate and nitrite exposure negatively impacted the visual system of adult zebrafish, highlighting the potential hazards of these environmental pollutants on aquatic organisms.

Cracking the code of the cardiovascular enigma: hPSC-derived endothelial cells unveil the secrets of endothelial dysfunction

Endothelial dysfunction is a central contributor to the development of most cardiovascular diseases and is characterised by the reduced synthesis or bioavailability of the vasodilator nitric oxide together with other abnormalities such as inflammation, senescence, and oxidative stress. The use of patient-specific and genome-edited human pluripotent stem cell-derived endothelial cells (hPSC-ECs) has shed novel insights into the role of endothelial dysfunction in cardiovascular diseases with strong genetic components such as genetic cardiomyopathies and pulmonary arterial hypertension. However, their utility in studying complex multifactorial diseases such as atherosclerosis, metabolic syndrome and heart failure poses notable challenges. In this review, we provide an overview of the different methods used to generate and characterise hPSC-ECs before comprehensively assessing their effectiveness in cardiovascular disease modelling and high-throughput drug screening. Furthermore, we explore current obstacles that will need to be overcome to unleash the full potential of hPSC-ECs in facilitating patient-specific precision medicine. Addressing these challenges holds great promise in advancing our understanding of intricate cardiovascular diseases and in tailoring personalised therapeutic strategies.

Application of Antioxidant Compounds in Bone Defect Repair

Bone defects caused by trauma, tumor resection, and infections are significant clinical challenges. Excessive reactive oxygen species (ROS) usually accumulate in the defect area, which may impair the function of cells involved in bone formation, posing a serious challenge for bone repair. Due to the potent ROS scavenging ability, as well as potential anti-inflammatory and immunomodulatory activities, antioxidants play an indispensable role in the maintenance and protection of bone health and have gained increasing attention in recent years. This narrative review aims to give an overview of the main research directions on the application of antioxidant compounds in bone defect repair over the past decade. In addition, the positive effects of various antioxidants and their biomaterial delivery systems in bone repair are summarized to provide new insights for exploring antioxidant-based strategies for bone defect repair.

Induction of Nitric Oxide and Its Role in Facial Nerve Regeneration According to the Method of Facial Nerve Injury

Nitric oxide (NO) is an important molecule in cell communication that also plays an important role in many biological processes. Given the dual role of NO in nerve degeneration and regeneration after facial nerve injury, we sought to delve deeper into its role through a systematic literature review. A comprehensive review of the literature employing SCOPUS, PubMed, Cochrane Library, EMBASE, and Google Scholar databases was conducted to evaluate the induction and role of NO in neurodegeneration and regeneration after facial nerve injury. From the 20 papers ultimately reviewed, the central findings were that neuronal nitric oxide synthase(nNOS), endothelial nitric oxide synthase (eNOS), and induced nitric oxide synthase (iNOS) increased or decreased depending on the method of facial nerve damage, damaged area, harvested area, and animal age, and were correlated with degeneration and regeneration of the facial nerve. Research conducted on rats and mice demonstrated that NO, nNOS, eNOS, and iNOS play significant roles in nerve regeneration and degeneration. However, the relationship between nerve damage and NO could not be defined by a simple causal relationship. Instead, the involvement of NOS depends on the type of nerve cell, source of NO, timing, and location of expression, age of the target animal, and proximity of the damage location to the brainstem. Consequently, nNOS, eNOS, and iNOS expression levels and functions may vary significantly.

Effects of dietary nitrate and vitamin C co-ingestion on blood pressure and hand-grip strength in young adults

Background: Co-administration of vitamin C and inorganic nitrate ([Formula: see text]) may reduce oxidative stress, boost the conversion of nitrite ([Formula: see text]) into NO and elicit positive vascular effects. Aims: We aimed to test the effects of oral inorganic [Formula: see text] and vitamin C co-supplementation on vascular function, muscular strength, and on concentrations of urinary [Formula: see text], vitamin C, 8-isoprostanes and salivary [Formula: see text] in healthy young adults. Methods: Ten young healthy participants were enrolled in a randomised, double-blind (only for the [Formula: see text] intervention) crossover clinical trial. Participants consumed in random order: 1) nitrate-rich beetroot juice and vitamin C (N+VC), 2) nitrate-rich beetroot juice alone (N) or 3) nitrate-depleted beetroot juice alone (ND). Resting blood pressure (BP) was measured at the research centre and at home. Non-invasive, continuous measurements of BP and cardiac function parameters were performed using a Finometer device. Free-living physical activity and hand-grip strength were assessed. Salivary [Formula: see text] and [Formula: see text] and urinary [Formula: see text], 8-isoprostanes and vitamin C concentrations were measured. Results: There were no significant differences for any of the vascular outcomes between the three interventions groups. However, analyses of within-intervention changes showed a significant lower daily systolic BP in the [Formula: see text]+vitamin C (N+VC) group only (P=0.04). Urinary [Formula: see text] (P=0.002) and salivary [Formula: see text] (P=0.001) were significantly higher in the N+VC group compared to the N and ND groups. Conclusion: These preliminary findings suggest that combining dietary [Formula: see text] with vitamin C could have protective effects on vascular function in young adults and could represent an effective strategy for the maintenance of healthy cardiovascular trajectories.

Total Nitrite and Nitrate Concentration in Human Milk and Saliva during the First 60 Days Postpartum-A Pilot Study

Nitric oxide (NO) in human milk may have important functions in lactation and infant health. This longitudinal pilot cohort study investigated the total nitrite and nitrate (NOx) concentration in human milk and maternal saliva during the first 60 days postpartum. Additionally, we explored the association between selected breastfeeding variables and milk and saliva NOx concentration. Human milk and maternal saliva samples were collected on days 2, 5, 14, 30, and 60 postpartum and analyzed for NOx concentration. Breastfeeding data were collected through self-assessed questions. Data analyses were performed using mixed models. The concentration of NOx in milk was significantly higher during the first 30 days compared to day 60, and there was a positive association between milk and saliva NOx concentrations throughout the entire study period. In absolute numbers, partially breastfeeding mothers had a lower concentration of NOx in milk on day 2 compared to exclusively breastfeeding mothers (8 vs. 15.1 μM, respectively). Partially breastfeeding mothers reported a later start of secretory activation and fewer mothers in this group started breastfeeding within the first hour after birth. Due to the small numbers, these differences could not be statistically evaluated. Further research is warranted to elucidate the role of NO in lactation success and breastfeeding outcomes.

Role of nitric oxide and signaling pathways modulating the stimulatory effect of snake venom secretory PLA2S on non-opsonized zymosan phagocytosis by macrophages

The phagocytic activity of macrophages activated with MT-II, a Lys-49 PLA2 homolog, and MT-III, an Asp-49 PLA2, from Bothrops asper snake venom, was investigated in this study using a pharmacological approach. Stimulating thioglycollate-elicited macrophages with both venom components enhanced their ability to phagocytose non-opsonized zymosan particles. MT-II and MT-III-induced phagocytosis was drastically inhibited by pretreating cells with L-NAME, aminoguanidine or L-NIL, cNOS or iNOS inhibitors, or with ODQ (sGC inhibitor) or Rp-cGMPS (PKG inhibitor). These results indicate that the NO/sGC/GMP/PKG pathway plays an essential role in the β-glucan-mediated phagocytosis induced in macrophages by these venom-secretory PLA2s.

High-intensity interval training in patients with glaucoma (HIT-GLAUCOMA): protocol for a multicenter randomized controlled exercise trial

Background

Glaucoma stands as a prominent global cause of irreversible blindness and the primary treatment approach involves reducing intraocular pressure (IOP). However, around one-third of patients exhibit disease progression despite effective IOP reduction. Microvascular endothelial function, chronic inflammation, and oxidative stress are known to affect retinal neuronal networks and have been associated with disease severity and progression. Exercise training has the potential to counteract these mechanisms as add-on treatment to usual care.

Aims

The HIT-GLAUCOMA study will investigate the effects of a 6-month high-intensity interval training (HIIT) on intermediate endpoints such as local retinal microvascular and systemic large artery function, inflammation, and oxidative stress as well as clinical endpoints such as visual field indices, optic nerve rim assessment, retinal nerve fiber layer thickness, IOP, number of eye drops, vision-related quality of life and ocular surface disease symptomatology.

Methods

The study is a multi-center randomized controlled clinical trial in patients with both normal tension and high-tension primary open angle glaucoma. Across two study centers, 128 patients will be enrolled and randomized on a 1:1 basis into an exercise intervention group and a usual care control group. The primary microvascular endpoints are retinal arteriolar and venular flicker light-induced dilation at 6 months. The primary endpoint in the systemic circulation is brachial artery flow-mediated dilation at 6 months.

Anticipated results

We hypothesize that exercise therapy will improve retinal microvascular function and thus ocular blood flow in patients with glaucoma. As clinical outcomes, we will investigate the effect of exercise on visual field indices, optic nerve rim assessment, retinal nerve fiber layer thickness, IOP, number of eye drops, vision-related quality of life and ocular surface disease symptomatology.

Discussion

HIT-GLAUCOMA is a blueprint trial design to study the effect of exercise training on neurodegenerative and cardiovascular diseases. Importantly, patients are also expected to benefit from improvements in general health and cardiovascular co-morbidities. If proven effective, exercise may offer a new add-on treatment strategy to slow glaucoma progression.

Clinical Trial Registration Number

The trial is registered at Clinicaltrials.gov under the identifier NCT06058598 and is currently in the recruitment stage.